Mass Deacidification: Effects of Treatment on Library Materials Deacidified by the DEZ and MG-3 Processes

Disclaimer

The information presented in this paper is the result of research
carried out on mass deacidified library materials between 1990 and
1991 while I was Preservation Officer at the Milton S. Eisenhower
Library of the Johns Hopkins University. Since moving to Princeton
University Libraries I have not kept up with all the advancements
and/or refinements in commercially available mass deacidification
technologies which might abrogate my research and consign it
footnote status in some future text on the history of these
processes. This presentation is made to the conservation field in
the spirit of fairness, fact, and information exchange, and also in
the spirit of being an informed and educated consumer, one who can
make decisions based squarely and entirely on fact.

Introduction

For several years a small number of libraries and consortia have
been involved with the testing and analysis of several
commercially-available mass deacidification technologies. a short
list of those involved includes: Harvard University; University of
Connecticut at Storrs; Harry Ransom Humanities Research Center,
University of Texas, Austin; Johns Hopkins University; the Library
of Congress; and the consortium of Midwestern libraries constituting
the Committee on Institutional Cooperation (CIC). Thousands of items
have been treated for and evaluated and tested by these
institutions: books, flat paper, and archival materials. the results
of and opinions about this work have been conveyed and exchanged
both formally and informally. By the time unpublished information
reaches the library and archives communities, however, it has little
more than anecdotal value to the institutions requiring solid,
reliable, and replicable data with which to make decisions. Little
has appeared in print which presents any institution's test data,
except for several recent publications by the Library of Congress,
the Association of Research Libraries, the CIC, and Harvard
University.1 in addition, the test
data presented in some of these reports has limited utility. Vendors
have provided more information to institutions about their mass
deacidification systems than the institutions testing these same
processes have provided to colleagues in their fields.

The Johns Hopkins and Harvard Universities have signed contracts
for mass deacidification services. During the Hopkins contract
signing, the library expressed confidence in both the process and in
the product, but without sharing data from its year-long testing
program with the news media to support its assurances. Although
health and safety concerns for staff and users were also not
mentioned, it must be implicit that these concerns had also been
assuaged to the Hopkins library administration's satisfaction.

The message being sent to the library and archives communities by
these contract signings is that mass deacidification works and that
it is OK for these institutions collections. My experience indicates
that it is not that simple. What is not being conveyed is straight
forward, unequivocal information about process effectiveness and
side effects on both materials and people. Very simply:

When do the mass deacidification processes work and how do they
work, and when do the processes not work and why?

Are there perceptible as well as imperceptible differences
between treated and untreated materials?

What are the effects of treatment and to what degree do they
occur? How many and what percentage of items are affected?

The short and simple answer to these questions is that all mass
deacidified materials were affected in some way by the two
commercially-available processes with which I am familiar: Akzo's
DEZ process and FMC/Lithco's MG-3 process.

The Johns Hopkins Experience With Mass Deacidification,
1990-1991

In my experience at the Milton S. Eisenhower Library of the Johns
Hopkins University the results of mass deacidification test runs on
typical library materials, what I have named the "effects of
treatment", were so startling that I had to wonder why these results
had not been known earlier, considering especially all the DEZ
research conducted by and for the Library of Congress on books since
the 1970s.

In some cases, the physical damage to some items was so great
that it required remediation, commercial rebinding, or replacement.
Covering material components--binding adhesives, cloth, paper, and
illustration colors and inks--were all affected to one degree or
another, depending upon the items selected for treatment. Book paper
cockled. All paper discolored somewhat and emanated an odor.
Hot-melt adhesives expanded or embrittled. Cold-melt adhesives
dissolved. With one process or the other, Selin call number labels
either bubbled and shriveled up or their adhesives oozed, precluding
treatment of retrospective collections labeled in this manner. Flat
paper, archival materials, and photographs were affected less so.
Some materials also were incompletely treated and remained acidic in
part. Charts 1 and 2
present empirical and statistical data compiled for 1,162 books mass
deacidified for Johns Hopkins by Akzo and FMC between May 1990 and
May 1991.

The photos on the following pages illustrate some of the effects
of treatment I have just glossed over

Photographs

Fig. 1 DEZ: Adhesive Effect

Figure 1: Adhesive Effect. the original hot melt adhesive melted
and bubbled beyond the top and bottom edges of this 1950s paperback.
the adhesive also expanded, pushing apart the textblock and cover.
(See also Figure 3.)

Fig. 2 DEZ: Flaking Cover Effect

Figure 2: Flaking Cover Effect. the flaking seen on this paper
covered hardback may be the result of an adverse reaction of a
pyroxylin (or some other) coating on the covering material to the
DEZ process.

Figure 4: Plastic Film Effect. Most clear plastic-like films
protecting the printing and paper covers of some paperbound books
were affected by delamination or bubbling, or, in this case,
brittleness and flaking.

Fig. 5 DEZ: Edge Burn Effect

Figure 5: Edge Burn Effect. the speculation for this effect is
that the book was not dried sufficiently/appropriately before
treatment. the excess moisture in the paper, attempting to migrate
out of the book, encountered DEZ gas at the edges of the textblock,
causing this chemical burn, due to the pyrophoric nature of diethyl
zinc gas.

Fig. 6 DEZ: Turn-in Staining Effect
pyroxylin (or some other) coating on this paper covered hardback or
to the type of adhesive used to adhere the covering material to the
boards.

Fig. 7 DEZ: Selin Label Effect

Figure 7: Selin Label Effect. All Selin labels affixed to
DEZ-treated books were affected in this manner. the clear plastic
tape overlay turned brittle and flaked, while the white tape
substrate buckled, puckered, and shrank. the white tape includes a
heat activated adhesive for affixing it to book covers. This
adhesive and the heat introduced/generated during the DEZ treatment
process probably caused this reaction.

Fig. 8 DEZ: Brittle Adhesive Effect

Figure 8: Brittle Adhesive Effect. This effect follows from
Figures 1 and 3. Normally flexible adhesive turned brittle after DEZ
treatment causing paperback books to break at opening points during
use. (All these books were manufactured in South America.) This
figure also illustrates a method to mark/stamp mass deacidified
books easily on the top edge of the textblock. the mark is a capital
"D" in a circle.

Fig. 9 MG-3: Ink Feathering Effect

Figure 9: Ink Feathering Effect. the CFC solvent used in the MG-3
process to carry the chemical to the books caused the ink of this
inscription to feather and smear.

Fig. 10. MG-3: Dissolving Adhesive Effect

Figure 10: Dissolving Adhesive Effect. The CFC solvent may have
caused a portion of the cold melt adhesives of these paperbacks to
dissolve at the cover-to-text attachment, releasing their covers.

Fig. 11 MG-3 Selin Label Effect

Figure 11: Selin Label Effect. in a number of cases the Selin
label adhesive dissolved slightly and a brown residue accumulated
around the edges and tops of the labels. in other cases only the
clear tape overlay bubbled.

Fig. 12 MG-3 Plastic Film Effect

Figure 12: Plastic Film Effect. Plastic film used to protect the
printed covers of paperbacks bubbled up and released easily from
their covers.

Fig. 13 MG-3 Page Discoloration Effect

Figure 13: Page Discoloration Effect. This effect was caused by
too much solvent remaining in the paper after treatment. in most
cases the page became slightly translucent/transparent.

Note: Some but not all of the process effects illustrated
above and listed in Charts 1 and 2 had low incidence occurrence, as low as one
instance during the entire Hopkins testing program. in other
instances, 100%, or nearly 100%, of the items tested in the testing
program were affected in a particular way: for example, odor,
cockling, paper discoloration. Low incidence occurrence is linked to
the number of like items treated at the same time. Low incidence
occurrence does not negate in any way that an effect took place. It
simply points out that, among other things: 1) a variety of
materials have been used in manufacturing publishers' bindings; 2)
the deacidification of some of these materials will be
problematical; 3) these materials are probably not deselectable
beforehand; and 4) that damage will result from their treatment.

As you have seen, as of May 1991 and based entirely on empirical
evidence from the Johns Hopkins test runs, mass deacidification
technologies had not been refined to the point where they would
transparently treat all paper-based materials, the ideal so long
held and hoped for by the library and archives preservation
communities. Deselection or pre-selection of items for treatment,
those which might be damaged or adversely affected, seemed necessary
in order to obtain the best possible and least damaging results on
the remaining but diminished pool candidates for mass
deacidification. It is doubtful, based on my experience at the time,
that DEZ or MG-3 would have been able to treat more than a limited
spectrum of the wide variety of books and other paper-based
materials which libraries and archives collect, house, and preserve.

Evaluating the Empirical Data

While gathering empirical data on the test runs I realized that
simply listing the effects of treatments and compiling statistics
about them alone would not wholly determine the viability of any
particular mass deacidification process to a library. As a result, I
developed a decision making model which can be used by an
institution's administration and preservation staff for reviewing
the empirical data to determine the acceptability of one or more
treatment effects on an institution's materials. (Refer to Chart 3.) I characterize this decision making
model in two ways. First, it is a vehicle to assess and perhaps
quantify possible risk, that is, damage, to collections materials.
in this way it is a risk management tool. Potential benefit may be
weighed against potential risk. Second, the model serves as a means
to establish a minimum level, or a threshold, of acceptable damage
to materials. This threshold, although not indicated on the chart,
can be expressed as a percentage or minimum number of items damaged
in some way or in particular ways per shipment or per year. an
institution would have to decide, based on the entire range of
possible undesirable and destructive treatment effects, what extent
of collection damage it would tolerate as a result of mass
deacidification treatment. Some damage translates into increased
expense because of the cost of additional handling and of
remediation, to repair or replace this items.

Conclusion

Conservators and preservation administrators cannot make
recommendations or decisions based on faith and hope. Promotional
materials provided and promises made by mass deacidification
vendors, anecdotes about treatment effects and empirical and
scientific test results, uninterpreted or incomplete test data, both
apparent and nonapparent physical damage and process defects, and
the actions of institutions and the opinions of colleagues cannot be
used as the sole sources of information by which important
collections preservation decisions are made. Open and public access
to and distribution of test results and analyzed data will allow
institutions with interest in this technology to make decisions
regarding its efficacy for the deacidification and preservation of
their collections as well as for the health and safety of their
staff and users. in addition, continuing unknowns about available
and future technologies should not discourage us from using and
benefiting from mass deacidification services, rather they should
encourage us to seek more information and become more informed
consumers before committing ourselves to any imperfect process. This
informed consumer approach will help those whose decisions will
permanently affect the usefulness and life of the collections they
were hired to manage, develop, preserve, and conserve.

References and Notes

1. Two of these references
were not available to me at the time of the AIC Annual Meeting. Full
citations for all the references follow:

** Not all items were affixed
with SELIN in every test run. in the third Akzo test run, 100% of
the books affixed with SELIN labels sustained label damage.

*** Almost 100% of the books
exhibited odor cockling and paper yellowing every shipment.

1. Materials selected for these trial
treatments represented bound materials in the Milton S. Eisenhower
Library's general collections and conformed to the Library's
selection policy for mass deacidification.

2. No totals are provided at the bottom of this
chart because many items exhibited multiple effects

* Remedial treatment may be
required, such as replacement, repair, commercial rebinding, or
second mass deacidification treatment, to correct effect of mass
deacidification.

** In-house materials
processing or shelf preparation procedures frequently introduce/add
new materials into a book, i.e. labels and property stamps.
Procedures may require revision to accommodate any potential damage
which might occur to these new materials as a result of mass
deacidification. for example, SELIN labels can be applied after
treatment.

Note: This chart reflects MSEL Preservation Department judgments
(at the time) regarding the impact of the effects of mass
deacidification on the selection, processing, use, life, and
soundness of materials.

* Remedial treatment may be
required, such as replacement, repair, commercial rebinding, or
second mass deacidification treatment, to correct effect of mass
deacidification.

** In-house materials
processing or shelf preparation procedures frequently introduce/add
new materials into a book, i.e. labels and property stamps.
Procedures may require revision to accommodate any potential damage
which might occur to these new materials as a result of mass
deacidification. for example, SELIN labels can be applied after
treatment.

Note: This chart reflects MSEL Preservation Department judgments
(at the time) regarding the impact of the effects of mass
deacidification on the selection, processing, use, life, and
soundness of materials.

Publication History

Received: Fall 1992

Paper delivered at the Book and Paper specialty group session, AIC
20th Annual Meeting, June 2-7, 1992, Buffalo, NY.

Papers for the specialty group session are selected by committee,
based on abstracts and there has been no further peer review. Papers
are received by the compiler in the Fall following the meeting and
the author is welcome to make revisions, minor or major.